I'm not so sure statistics-wise if you can call it just good luck. It's been so long since I studied this kind of stuff, but I was always amazed at how small a sample size could be to give a pretty good estimation. If I recall, it has something to do with the bell curve and standard deviation. Maybe that doesn't apply to poker, but I'm not sure why.
Just look at the presidential polls -- they'll ask a sample size of around 1,000 people and be able to predict within a few percentage points how the whole population would vote.
I think you'll be fine. You've shown that you are doing something right. Just make sure you have a lot of buy-ins for the next level before you give it a try. When I say a lot, I mean whatever you can handle that won't make you play like you are scared of losing. I think that has to be different for everyone depending on their aversion to risk. Mine is actually 100. And don't forget that you can move back down if you go under your required amount. In fact, demand it of yourself.